DE-A-39 20 377 discloses a large round baler with a baling chamber of constant size that is surrounded around its circumference by rollers extending horizontally. The rollers of a forward group are supported, free to rotate, in bearings carried by a fixed housing part, while the remaining rollers are supported, free to rotate, in bearings carried by a rear housing part that is pivoted vertically. The pivoted, rear housing part is provided with a locking hook that opens diametrically towards the center of the baling chamber. The end faces of the baling chamber are closed by circular end face walls that are supported in bearings, free to rotate, by means of a shaft in a pivoting frame. The pivoting frame can be pivoted outward about two bearings or it can be retained in an inward end position. The pivoting frame can be arrested by the locking hook that overlaps the pivoting frame and fixes it toward the outside. Furthermore the side walls are driven in order to improve the process of building a bale. If the side walls deflect outward according to this known arrangement as a result of the opening of the baling chamber, the pressure on the end faces of the cylindrical bale is reduced along with the friction resulting therefrom, so that the cylindrical bale can roll out of the baling chamber without any problems.
From U.S. Pat. No. 4,334,467, a large round baler is also known, this time however, with a baling chamber of variable size, whose side walls can rotate and one of which can be repositioned towards the longitudinal centerline of the large round baler. The repositioning of the particular side wall is performed by means of a hydraulic motor and also has the intent of reducing the friction forces on the bale during the ejection process.